Attention: Depending on the version of the carburetor, 2 idle shutoff valves with different functions are installed.
The idle shutoff valve shuts off the fuel supply to the fuel jet when the ignition is turned on or when the highest speed of 6100±50 rpm is reached. In this case, the current flow is regulated by a delay relay. As long as no voltage is applied, the valve is always open. After the ignition is turned off, the relay ensures that voltage is applied for 6 to 16 seconds, as a result of which the valve closes the fuel supply during this time. The valve then opens on its own again. In addition, the CO content is regulated by a valve. With a defective valve, the engine runs after the ignition is turned off for a while. When the valve is stuck" closed, the engine will not start. The idle shutoff valve is screwed into the float chamber under the carburetor.
The engine will not start
Remove the plug (1) with idle shutoff valve (9).
Connect the test lamp to the plug and ground.
Turn on starter. The lamp should not light up. If the lamp comes on with the ignition on or while the starter is running, check the idle air shutoff valve relay.
Attention: After turning off the ignition, the lamp should burn for 6-16 seconds.
Connect the test lead to the positive pole of the battery and alternately connect and disconnect it from the contact of the shut-off valve. At the same time, the valve should click, otherwise check the connection to the mass of the carburetor.
Caution: If the valve clicks but the engine does not start, tap the valve hard and start the engine. Also, if the engine starts in this case, replace the valve as soon as possible.
The engine does not stop immediately after turning off the ignition
Engine at operating temperature, oil temperature 65-75°C.
Start the engine and leave at idle.,
Remove the plug from the idle shutoff valve. Connect the contact of the valve plug with an auxiliary wire. The engine must stop, otherwise check the ground connection on the carburetor, if there is contact, replace the valve.